Magnetic clutch.



No. 754,291. PATENTED MAR. 8, 1904.

A. C. BASTWOOD.

MAGNETIC CLUTCH. APLIoA'rIoN Hum JAN. se, 1904.

xo MODEL.

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UNITED STATES Patented March 8, 1904.

PATENT OFFICE.

MAGNETIC CLUTCH.

SPECIFICATION forming part of LettersPatent No. 754,291, dated larch 8, 1904. Application led January 26, 1904. Serial No. 190,724 (No model.)

To all whom it 'may concern:

Be it known that I, ARTHUR C. EAs'rwooD, a citizen of the United States, residing in Cleveland, Ohio, have invented certain Improvements in Magnetic Clutches, of which the following is a specication. Y

My invention relates to certain new and useful improvements in magnetic frictionclutches, the object of the same being to provide a clutch of such construction that it shall be relatively powerful in proportion to its size and weight.y

A further object of the invention isl to so arrange the various parts of a clutch that it will dissipate relatively large amounts `ci energy in the form of heat without danger of injury to itself.

It is further desired to provide a device in which the magnetizing-coil shall be stationary and independent of the frictional members of the clutch, thereby doing away with the necessity for brushes and contact-rings, Otherwise necessarily said coil.

It is also desired to so arrangethe parts of a clutch of the general construction outlined above that the magnetic pull will be balanced along the shaft in such manner as not to cause end thrust upon the bearings.

These objects I attain in the manner hereinafter set forth, reference being had to-the accompanying drawingin which the figure is a sectional elevation taken through the supporting-shaft and illustrating in detail the construction of my improved clutch'.

The most common form of magnetic-clutches at present in use includes an annular electromagnet with an armature-plate of disk form mounted upon a common shaft, one of these members being keyed to said shaft and the other loosely mountedl thereon, so that it may be free to revolve. Power is usually transmitted from a source of power to the magnet, and when this is energized it attracts and is operatively coupledto the armature which is permanently attached to the apparatus tobe driven.Y In thisl form of clutch current must be led t9@ magnetizing-coil of the clutch-v magnet through brushes bearing upon .a pair of collector-rings, the insulation and mountemployed to convey current ings of which as well as that of the revolving magnetizing-coil forming considerable items of expenditure both as regards their first cost as well as their maintenance. In my improved clutch since vthe magnetizing coil or coils is stationary both the collector-rings and brushes are altogether dispensed with, it being noted that for this same reason said coil is not subjected to the action of centrifugal forceand may consequently be -of a much less costly construction than has hitherto been employed. Further, in the common forms of clutches there is a frictional contact between one of the' polefaces of the electromagnet and the armaturedisk, and when the driven member of the clutch is attached to 'a load and the driving member is serious item, since it is possible that it may be produced faster than it can bdissipated,.-

with the result that the temperature of the clutch will continue to rise until the coil or some other part of the clutch is injured. This tendency is particularly noticeable when the clutchis used in connection with a metal planer operating' on a short stroke, the conditions bebined 4mass in an opposite direction -It will be understood that on avery short stroke this transferrence of energy becomes practically continuous, so that serious injury would certainly be done, and one of the advantages of my limproved structure is that it is so constructed as to simply and effectually dissipate third standard a', carrying a ring-shaped piece IOO of iron or steel a2, within which is wound' the magnetizing-coil as, this latter being heldinposition within the ring in any of the Wellknown ways and beingprovided with terminals (not shown) through which it is supplied with current.

Keyed to the shaftB is an armature-disk C, having a cylindrical portion c extending through and beyond the magnetizing-coil a3, there being upon the end of said extended portion c a ring o' of some non-magnetic material, such as brass. In addition there is also keyed to the shaft B at the end of the extended cylindrical portion of the armature-disk a plate D of magnetic material, having a diameter preferably the same as that of said disk.

Keyed or otherwise fixed to the brass ring c' are any desired number of rings c2, in the present instance two, there being interposed between these and also between one of them and the end disk D other rings e, keyed or otherwise operatively fixed to the second member of the clutch'E, whose external surface is preferably formed with corrugations or other equivalent construction by which a large amount of heat-radiating surface may be obtained. The end e of this member E, I preferably extend inwardly between one of the rings c2 and the face of theixed magnetizin'gring a2, so as to form an inclosed luid-tight casing around the various rings. `I also provide a gear e2, keyed to the member E, whereby power may be transmitted to any mechanism or apparatus which it is desired to drive.

When under ordinary conditions the shaft B, with its connected parts, is driven from a source of power and the magnetizing-coil a3 is supplied with current, the iow of the lines of force will take place, as indicated,through the armature-disk C and its portion c, the

disk D, the rings e and 02, and through the ring a2, thereby causing said rings e and cf2 to be drawn together with a heavy pressure and effectually coupling the member E to the armature C, and consequently to the shaft B.

The joint between the inwardly-projecting portion e and the brass ring c is liquid-tight, and the interior of the case E is filled with oil or other liquid which not only lubricates the various rubbing surfaces, but also serves to conduct heat generated by friction of said surfaces to the outer portions of the case, from which it will be rapidly radiated by the corrugations or other extended surfaces. It will further be noted that all of the magnetic lines of force pass through the armature C, disk D, and case E, with their attached parts, .in vsuch a manner that the pull exerted will have an equal effect on both of the revoluble members of` the clutch, Tso that they will be in equilibrium relatively to the fixed coil a3 and its supporting pole-piece a2. Hence there will be no unbalanced thrust along the shaft and no tendency for any of the parts to be drawn against said pole-piece a2.

I claim as my invention- 1. A magnetic clutch including two revo lubly-supported members, each having a series of rings fixed to it with a stationary coil placed to act on said rings to operatively couple the members, substantially as described.

2. A clutch having two members constructed to frictionally engage each other, a casing inclosing the engaging surfaces of said members, liquid in said casing, and a magnet for drawing said two members together, substantially asdescribed. 4

3. A stationary magnet, two members constructed to I frictionally engage each other and placed to be drawn together by said magnet, with a casing inclosing said members and a liquid in said casing, substantially as described.

4. The combination of a lixed magnet, a pair of rings of magnetizable aterial both on the same side of the magne and connected respectively to the driving and driven apparatus with an armature on the opposite side of the magnet from the"rings,`substantially`as described.

5. The combination in a clutch of a fixed magnetizing-coil, a flanged body of metal ex tending through said coil, a ring of non-mag- .netic metal adjacent .to the coil, a series of rings of magnetizing material on said first ring, a second series of rings of magnetizing material, independent of the other series, s aid rings being placed tobe included in the magnetic circuit of Vthe magnet, substantially as described. y

6. The combination of two series of parallel rings, supporting-pieces Jf'or each of said sets of rings, certain of the same forming a closed casing, with a magnet and a core therefor, saidmagnet being placed to include the rings in its magnetic circuit, substantially as described. e

7. The combination vof a casing having a surface provided with projecting portions, bodies of metal attached to said casing, an armature having portions within said casing placed to coact with the bodies of metal therein, liquid in the casing and a magnet placed to act on the armatureand on the bodies of metal coacting with the same to draw them together, substantially as described.

8. The combination of a liquid-tight casing having a portion operatively connected to a driving device and another portion connected to a driven device, frictionally-c'oacting bodies of metal within the casing and connected to its respective parts, with a'magnet placed to act on the said bodies of metal to draw them together, substantially as described.

9. The combination of a ring of magnetizable metal, a coil supported thereby in a fixed position, a diskrevolubly supported on one side of the coil having a portion extending through the same, a body of non-magnetizable metal on said portion, ametallic ring on IOO IIO

said body of metal, a second disk also having a metallic ring coacting with the other ring with means for dissipating heat generated by the frictional engagement of said two rings, substantially as described.

10. A clutch'having members constructed to frictionally engage each other to couple a driving with av driven device, means for causing said members to grip each other, anda casing surrounding the members, with liquid in the casing bathing portions of the said members, substantially as described.

l1. A clutch having members constructed to frictionally engage each other to couple a driving with a driven device, means for causing said members to grip each other, and a casing surrounding the members, with a liquid in the casing bathing portions of said members, said casing' having its peripheral portion roughened and made with a relativelyy eX- tended surface, substantially as described.

12. The combination of a casing having within and fixed to it a metallic ring,7 a shaft passing through the casing and also having a ring fixed to it, an armature coacting with one of the rings and a relatively stationary magnet placed to act on said rings and armature, substantially as described.

13. The combination of a shaft havingon it an armature -plate and a series of rings, a sleeve also on said shaft having connected to it a second series of rings placed to coact with those of the first series, means for 'connecting the shaft and the sleeve between av driving and a driven device, with a magnet between the armature-plate and said two series of rings, substantially as described.

In testimony whereof I have signed my name to this speciiication in the presence of two subscribing witnesses. v

ARTHUR C. EASTWOOD. Witnesses:

' C. W. CoMs'rocK, J. E. W ELLMAN. 

